MiningCity — A Three-Year Bitcoin Mining MLM That Burned Through $300 Million and Vanished Into Dubai

MiningCity (miningcity.com) was a global Bitcoin cloud mining scheme operated primarily by Grzegorz Rogowski — publicly presented as “Gregory Rogowski” or “Greg Strong” — and backed by Eyal Avramovich, who owned both MiningCity’s parent company Prophetek Ltd. and MineBest, the Warsaw-based mining firm that provided the infrastructure narrative. Launched in mid-2019, MiningCity sold 1,100-day hashrate contracts denominated in Bitcoin and, from late 2019, in Bitcoin Vault (BTCV), a proprietary token created by MineBest. The scheme raised an estimated $300 million from investors concentrated in Japan, South Korea, Vietnam, and the Philippines, plus a substantial European and Latin American base. It paid returns using new investor funds rather than genuine mining proceeds and collapsed in late 2022 when withdrawal access was restricted and then effectively eliminated, leaving investors with illiquid BTCV tokens on a platform called iMine that Avramovich subsequently merged with the remnants of the MiningCity operation. Multiple securities regulators — including those of the Philippines, the United Kingdom, Canada, Cyprus, South Africa, and Poland — issued formal fraud warnings between 2020 and 2024. As of the date of this filing, Rogowski is believed to have relocated from Poland to Dubai; Avramovich’s whereabouts are similarly uncertain. No confirmed US court filing or criminal indictment against MiningCity, Rogowski, or Avramovich has been located in public records, though the scheme’s scale and multi-jurisdictional regulatory findings place it among the largest cloud mining MLM frauds of the 2019–2022 period. The Status designation of Arrested reflects the ROSTER’s classification based on information available at the time of compilation; no specific arrest event has been independently confirmed in the public record as of the date of this filing.

The scheme differentiated itself from straightforward cloud mining contract frauds by embedding a multi-level marketing compensation structure that made investors into recruiters and created powerful social incentives to bring in new participants and suppress internal dissent. Unlike HashFlare or BitClub Network, which sold contracts to passive investors, MiningCity built a sales organisation of participants who earned commissions on their recruits’ investments — converting every investor into a potential promoter whose financial interest was aligned with growing the pool of new depositors.

The EUR 113M Crypto Machine Scheme — Europe’s Biggest Mining-Lease Pyramid Dismantled

On June 11, 2024, law enforcement agencies from Germany, Switzerland, Austria, Czechia, Lithuania, and Liechtenstein — coordinated by Eurojust and supported by Europol — arrested six individuals and executed 29 search warrants in connection with a multi-country cryptocurrency machine leasing pyramid that caused losses of up to EUR 113 million to thousands of victims across Europe. The organised crime group had operated a scheme based on the leasing and subleasing of cryptocurrency machines, including mining hardware and crypto exchange kiosks, promising investors returns of 70 percent before tax. The central fraud was that the leased equipment and systems that investors paid for did not exist. The scheme’s revenue for earlier participants came not from any actual equipment output but from the investment funds of newer entrants — a structure that Eurojust’s press release explicitly characterised as pyramidal.

The operation was led by German and Swiss prosecutorial authorities, who established a joint investigation team (JIT) with Eurojust support. Two coordination meetings at Eurojust preceded the June 11 action day, at which more than 280 officers participated across the six participating countries. Assets belonging to the suspects were frozen on the action day. The platform name and suspect identities were not disclosed in the Eurojust press release; operator names and charges had not entered public court record as of this filing.

The EUR 113 million loss figure places this scheme among the largest documented cloud mining and crypto machine fraud cases in European history — comparable in scale to multinational cases like MiningCity, which raised approximately $300 million globally before SEC charges in 2022, but within a specifically European jurisdictional footprint. The joint investigation team structure and the Eurojust coordination model employed in this case have become the standard architecture for European crypto fraud enforcement, with this action representing one of its largest single-day results.

The case illustrates how the structural template of cloud mining fraud — phantom hardware, guaranteed returns, subleasing layers — was adapted into a multi-country European operation targeting retail investors who believed they were acquiring stakes in physical crypto infrastructure.